Azo dye.



M UNITED STATES PATENT OFFICE.

PAUL JULIUS AND CARL IMMERHEISER, 0F LUDWIGSHAFEN-ON-THE-RHI1\TE, GER-MANY, ASSIGNORS TO ZBADISCHE ANILIN & SODA FABRIK, 0F LUDWIGSHAFEN-ON-THE-BHINE, GERMANY, A CORPORATION.

AZO DYE.

No Drawing.

To all whom it may concern Be it known that we, PAUL JULIUS and CARL'IMMERHEISER, citizens, respectively, of the AustroHungarian Empire andof the German Empire, residing at Ludwigshafen- 'on-the-Rhine, Germany,have invented new and useful Improvements in Azo Dyes, of which thefollowing is a specification.

Wehave discovered a new coloring matter which can be produced bycombining diazotized meta-tolujdin with bcnz0yl-L8- amino naphthol 4.6disulfonic acid, and which is very valuable in the form of its lakes.

One of the characteristics of our new coloring matter isthat on gentlereduction with stannous chlorid and hydrochloric acid, it gives rise tometa-toluidin and an amino compound of benzoyl-1.8-aminonaphthol-Mli-disulfonic. acid.

The" following example will serve to illustrate further the nature ofour invention, which, however, is not confined to this example. Theparts are by weight. Diazotize 107 parts of meta-toluidin (which may bedone in the usual manner) and run the solution, while stirring, into asolution of 467 parts of the disodium salt of benzoyl1.8-amino-naphthol-4fi-disulfonic acid, to which an excess of sodiumcarbonate has been added. When the combination is complete, heat themass to about 80 G., add common salt, if necessary, and then filterSpecification of Letters Patent.

Application filed Max 28, 1913. Serial No. 770,328.

Patented Sept. 23, 1913.

off and press and dry the coloring matter. It is a violet-red powderwhich dissolves in water, the solution being brilliant red.

In the form of its alkaline earth lakes, it'

water and in the form of its alkaline earth lakes possesses brilliantblue-red shades, and which upon gentle reduction with stannous chloridand hydrochloric acid gives riseto' meta-toluidin and an aminoderivative of beny'oyl 1.8 amino naphthol 4.6 disulfonic acid.

In testimony whereof we have hereunto set our hands in the presence oftwo subscribing witnesses.

PAUL JULIUS. CARL IMMERHEISER.

Witnesses:

J. Anne. LLoYn, J osnrn Prmrrnn.

